High performance/high availability client-server computing systems often employ multiple application server devices. Often multiple servers are used provide a services or applications to many client devices. Network traffic management devices (e.g., load balancers) may be used to distribute client requests to one or more of the servers. Network traffic management devices (TMDs) may be arranged so the identity and/or quantity of servers available to process requests may be transparent and unknown to the client devices. Accordingly, TMDs receive client requests and forward the requests the appropriate servers. If servers respond to client requests, they send the responses to the TMD and the TMD may forward these responses to the appropriate client devices. The TMD may maintain state information that enables the server responses to be forwarded to the appropriate client devices. In some cases, a server that is configured to communicate through a TMD may be required to initiate a communication session by sending a first request to a client device. Thus, it is with respect to these considerations and others that the invention has been made.